Ok so it seems all my writer friends have a universe split into components, whether it be elements (most common) or one girl did cards. So mine was seasons.

Spring:
-don't remember what they did as export? maybe cotton and clothing?
-tend to have brown hair

Summer:
-live by the beaches. primary export is from fishing and fish farming. they also have more tropical plants (i.e. coconut trees) as resources.
-they're considered the most relaxed people in the kingdoms
-due to high exposure to the sun, they tend to have darker skin

Autumn:
-hardworking people who rely mainly on agriculture and livestock to survive
-dark hair, smol eyes

Winter:
-villages in the mountains, primary export is from mining/ manufactured products
-most people are blonde with blue or green eyes and very pale

and my plot was two of the kingdoms needed to join forces and end the bickering between the kingdoms. so the main character, Aria, princess of (????) is forced to marry some random dude (another prince), but she doesn't want to. unfortunately the other princesses are not of age to be married (and also her kingdom wants to be one of the two to seize power). so she like devises a plan to flee with this other dude, who is her best friend (Edwin? LOL) but also a prince from yet another kingdom. the final kingdom doesn't really do anything because i think they have twin boys that are like five years old.

EDIT:

This entire universe is a universe within a universe. The beginning of the story opens with Jake, a young boy who loves to read. He is babysat by a lady who owns the local bookstore. She opens the book and sits him down, telling him the story of the Season Kingdoms.